• 제목/요약/키워드: Grafting

검색결과 1,536건 처리시간 0.029초

UV-Induced Graft Polymerization of Polypropylene-g-glycidyl methacrylate Membrane in the Vapor Phase

  • Hwang, Taek-Sung;Park, Jin-Won
    • Macromolecular Research
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    • 제11권6호
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    • pp.495-500
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    • 2003
  • UV-induced graft polymerization of glycidyl methacrylate (GMA) to a polypropylene (PP) membrane was carried out in the vapor phase with benzophenone (BP) as a photoinitiator. Attenuated total reflection Fourier transform infrared spectroscopy, atomic force microscopy (AFM), and scanning electron microscopy (SEM) were utilized to characterize the copolymer. The degree of grafting increased with increasing reaction time, increased UV irradiation source intensity, and increased immersion concentration of the BP solution. The optimum synthetic condition for the PP-g-GMA membrane was obtained with a reaction time of 2 hrs, a UV irradiation source intensity of 450 W, and an immersion concentration of the BP solution of 0.5 mol/L. The pure water flux decreased upon increasing the degree of grafting and increasing the amount of diethylamino functional group introduced. The analysis of AFM and SEM images shows that the graft chains and diethylamino groups of PP-g-GMA grew on the PP membrane surface, resulting in a change in surface morphology.

Refractory Coronary Artery Spasm after Minimally Invasive Direct Coronary Artery Bypass Grafting

  • Ju, Min-Ho;Kim, Joon-Bum;Kim, Hee-Jung;Choo, Suk-Jung
    • Journal of Chest Surgery
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    • 제44권4호
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    • pp.288-291
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    • 2011
  • Postoperative coronary arterial spasm is a rare but potentially fatal complication. A 51-year-old male patient with a history of a reactive ergonovine stress test coronary angiogram developed refractory coronary artery spasm after undergoing minimally invasive direct coronary artery bypass grafting of the left anterior descending coronary artery. The patient was successfully managed with rapid implementation of intra-aortic balloon-pump counter pulsation and extracorporeal membrane oxygenation.

반응성 염료의 광그라프트에 의한 양모직물의 염색 (Photo-grafting Dyeing of Wool Fabrics with Dimethacrylated Quinizarin Dye)

  • 동위엔위엔;장진호
    • 한국염색가공학회:학술대회논문집
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    • 한국염색가공학회 2012년도 제46차 학술발표회
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    • pp.26-26
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    • 2012
  • The hydrophobic nature of the wool surface give rise to difficult penetration of dye molecules. Among all the methods of modification, graft polymerization is an attractive method to impart a variety of functional groups to a polymer. Grafting has been made by irradiating the light on the polymer in the presence of a solvent containing monomer. The energy source commonly used are high-energy electrons, X-rays, UV and visible light. UV irradiation is a relatively low-energy radiation in comparison with others since it has the least possibility to change bulk properties. In the present paper, a photo-reactive dye was synthesized from quinizarin by the reaction with methacryloyl chloride. The synthesized dye was continuously grafted onto wool fabric at room temperature by UV irradiation. Several key parameters including UV energy, dye concentration and pH have been examined to understand their influence on the photoreactive coloration.

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Photografting of PET Fabrics with Vinyl Pyrrolidone and Acryloyl Morpholine Monomers

  • Huang, Weiwei;Jang, Jin-Ho
    • 한국염색가공학회지
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    • 제20권5호
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    • pp.28-34
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    • 2008
  • PET fabrics were photografted under continuous UV irradiation with vinyl pyrrolidone (VP) and acryloylmorpholine(ACMO) as monomers and benzophenone as a hydrogen-abstractable photoinitiator. ACMO can be grafted onto the PET fabrics more efficiently than VP. The grafted PET surfaces were characterized by ATR, ESCA, SEM and zeta potential measurement. ATR and ESCA analysis indicated significant alterations on chemical structure and atomic composition on the surface of the grafted fabrics, where nitrogen content increased with increasing grafting yield. SEM images showed that the fabric surface was covered with the grafted polymers. The zeta potentials and the water wettability of the grafted PET increased with grafting. Also the photografted fabrics showed an increased dyeablity to reactive dyes and increased affinity to various iodine species which imparted anti-bacterial properties.

경동맥 절제후 혈관치환술을 시행한 경동맥체 종양 (SURGICAL RESECTION OF CAROTID BODY TUMOR WITH CAROTID ARTERY REPLACEMENT)

  • 최건;이은수;정광윤;최종욱
    • 대한기관식도과학회지
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    • 제2권2호
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    • pp.280-284
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    • 1996
  • Carotid body tumors are uncommon tumors of the head and neck Surgery is the primary treatment for the tumor. Large carotid body tumors frequently encircle the common, internal, and exernal carotid arteries, and extensive bleeding often complicates the resection, increasing the risk of carotid artery rupture and damange to major cranial nerves. Grafting should be used in high-risk patients. We have experienced a case of carotid body tumor which encircle the common, internal and external carotid arteries, treated with ligation of external carotid artery and grafting using Gortex between common carotid artery and internal carotid artery.

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폴리에틸렌테레프탈레이트/에틸렌-메틸아크릴레이트-글리시딜 메타크릴레이트 공중합물 블렌드의 결정화 거동 (Crystallization Behavior of Poly(ethylene terephthalate)/Ethylene-Methyl acrylate-Glycidyl methacrylate Copolymer Blend)

  • 성상엽;이종관;이광희;진병석
    • 폴리머
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    • 제25권6호
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    • pp.848-854
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    • 2001
  • 무정형 고분자인 ethylene-methyl acrlate-glycidyl methacrylate 공중합체 (E-MeA-GMA)와 결정성 고분자인 poly(ethylene terephthalate) (PET)와의 블렌드에서 그라프트 반응에 따른 PET의 결정화 거동을 조사하였다. PET와 E-MeA-GMA간의 그라프트 반응 수준을 torque-rheometer, FT-IR, SEM을 이용하여 확인하였으며, 반응시간에 따른 결정화 거동 변화를 DSC와 광산란 방법을 이용하여 관찰하였다. 또한 라멜라 수준의 결정구조를 소각 X선 산란법을 이용하여 조사하였다.

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Post-Coronary Artery Bypass Grafting Myocardial Ischemia Caused by an Overgrown Left Internal Thoracic Artery Side Branch

  • Kim, Eung Re;Oh, Se Jin;Kang, Hyun-Jae;Kim, Ki-Bong
    • Journal of Chest Surgery
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    • 제47권5호
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    • pp.465-467
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    • 2014
  • We present a patient who developed recurrent angina after coronary artery bypass grafting (CABG). Myocardial single-photon emission computed tomography (SPECT) demonstrated deterioration in the myocardial perfusion, and coronary angiography revealed an overgrown side branch of the grafted left internal thoracic artery (ITA); otherwise, there were no significant changes compared with previous imaging studies obtained after the CABG. After percutaneous embolization of the grafted left ITA side branch, the angina was resolved and myocardial SPECT showed improved perfusion.